Cause Of Discomfort Research Articles

Analysis of human body vibration response on high-speed trains under crosswinds

The increase in the speed of high-speed trains and the widespread use of lightweight vehicle body technology have made vehicle systems more sensitive to aerodynamic excitation. However, few studies have focused on the worsening of passenger ride comfort, as opposed to just safety, when trains pass along windy railway lines. This study first analyzes the connection between flow structure and aerodynamic load, using bidimensional empirical mode decomposition (BEMD). Then, it examines the effect of aerodynamic loads on the vibration characteristics of vehicles and human bodies, at different speeds under crosswinds, by combining a vehicle-track-seat-human body coupling model. Finally, the effects of crosswinds on vehicle and human body vibration are analyzed, including differences in vibration characteristics of the human head when in different positions. The BEMD results indicate that the flow field around the vehicle is dominated by low-frequency oscillation. These low-frequency components show close alignment with the aerodynamic loads’ main frequency, and the high-speed trains’ natural frequency, which may lead to vehicle resonance shaking, and to derailment. Additionally, it is found that lateral vibration comfort for human legs and thighs is worst in both the head and middle cars, while vertical vibration comfort for the human head is worst in the head car. When running at three speeds under crosswinds, fluctuations in aerodynamic loads and track irregularities are major causes of discomfort for humans, particularly affecting vertical vibration comfort. In crosswinds, vertical vibration of the human head is significantly greater than lateral vibration, indicating a loss of comfort, primarily in the vertical direction, when trains are excited by crosswinds. It is observed that lateral vibration comfort is worst at the front end of the head car, but best at their rear end. Vertical vibration comfort is best in the middle section of the head car.

The effect of ultrasound-guided rectus sheath block on postoperative analgesia in robot assisted prostatectomy: A randomized controlled trial.

Postoperative pain continues to represent an important problem even after minimally invasive robotic-assisted laparoscopic radical prostatectomy, which results in discomfort in the postoperative period and sometimes prolongs hospital stays. Regional anesthesia and analgesia techniques are used in addition to systemic analgesics with the multimodal approach in postoperative pain management. Ultrasound-guided fascial plane blocks are becoming increasingly important, especially in minimally invasive surgeries. Another important cause of discomfort is urinary catheter pain. The present randomized controlled study investigated the effect of rectus sheath block on postoperative pain and catheter-related bladder discomfort in robotic prostatectomy operations. This randomized controlled trial was conducted from March to August 2022. Written informed consent was obtained from all participants. Approval for the study was granted by the Clinical Research Ethics Committee. All individuals provided written informed consent, and adults with American Society of Anesthesiologists Physical Condition classification I to III planned for robotic prostatectomy operations under general anesthesia were enrolled. Following computer-assisted randomization, patients were divided into 2 groups, and general anesthesia was induced in all cases. Rectus sheath block was performed under general anesthesia and at the end of the surgery. No fascial plane block was applied to the patients in the non-rectus sheath block (RSB) group.Postoperative pain and urinary catheter pain were assessed using a numerical rating scale. Fentanyl was planned as rescue analgesia in the recovery room. In case of numerical rating scale scores of 4 or more, patients were given 50 µg fentanyl IV, repeated if necessary. The total fentanyl dose administered was recorded in the recovery room. IV morphine patient-controlled analgesia was planned for all patients. All patients' pain (postoperative pain at surgical site and urethral catheter discomfort) scores and total morphine consumption in the recovery unit and during follow-ups on the ward (3, 6, 12, and 24 hours) in the postoperative period were recorded. Sixty-one patients were evaluated. Total tramadol consumption during follow-up on the ward was significantly higher in the non-RSB group. Fentanyl consumption in the postanesthesia care unit was significantly higher in the non-RSB group. Total morphine consumption was significantly lower in the RSB group at 0 to 12 hours and 12 to 24 hours. Total opioid consumption was 8.81 mg in the RSB group and 19.87 mg in the non-RSB group. A statistically significant decrease in urethral catheter pain was noted in the RSB group at all time points. RSB exhibits effective analgesia by significantly reducing postoperative opioid consumption in robotic prostatectomy operations.

Machine learning-based prediction of tear osmolarity for contact lens practice.

This study addressed the utilisation of machine learning techniques to estimate tear osmolarity, a clinically significant yet challenging parameter to measure accurately. Elevated tear osmolarity has been observed in contact lens wearers and is associated with contact lens-induced dry eye, a common cause of discomfort leading to discontinuation of lens wear. The study explored machine learning, regression and classification techniques to predict tear osmolarity using routine clinical parameters. The data set consisted of 175 participants, primarily healthy subjects eligible for soft contact lens wear. Various clinical assessments were performed, including symptom assessment with the Ocular Surface Disease Index and 5-Item Dry Eye Questionnaire (DEQ-5), tear meniscus height (TMH), tear osmolarity, non-invasive keratometric tear film break-up time (NIKBUT), ocular redness, corneal and conjunctival fluorescein staining and Meibomian glands loss. The results revealed that simple linear regression was insufficient for accurate osmolarity prediction. Instead, more advanced regression models achieved a moderate level of predictive power, explaining approximately 32% of the osmolarity variability. Notably, key predictors for osmolarity included NIKBUT, TMH, ocular redness, Meibomian gland coverage and the DEQ-5 questionnaire. In classification tasks, distinguishing between low (<299 mOsmol/L), medium (300-307 mOsmol/L) and high osmolarity (>308 mOsmol/L) levels yielded an accuracy of approximately 80%. Key parameters for classification were similar to those in regression models, emphasising the importance of NIKBUT, TMH, ocular redness, Meibomian glands coverage and the DEQ-5 questionnaire. This study highlights the potential benefits of integrating machine learning into contact lens research and practice. It suggests the clinical utility of assessing Meibomian glands and NIKBUT in contact lens fitting and follow-up visits. Machine learning models can optimise contact lens prescriptions and aid in early detection of conditions like dry eye, ultimately enhancing ocular health and the contact lens wearing experience.

Thermal comfort inside a gable-roofed metallic shed in a higher educational institution: a case study and detailed analysis

Abstract Central workshop is an integral part of any higher education institution, and it will be generally operated in a gable-roofed metallic shed. The users of the building are affected physiologically and psychologically due to the thermal discomfort conditions caused by improper ventilation. It is necessary to study the cause for discomfort and propose cost and effective methods to mitigate the problem. In this work, the thermal comfort inside a gable-roofed workshop was analyzed, and it was found that the discomfort was predominant from 2 PM to 5 PM. It was predicted that the conduction heat transfer could be reduced upto 55% with the help of passive cooling technique carried out using aluminium bubble wrap. During the life cycle cost study, the aluminium bubble wrap technique was found to be more economical over high-volume low-speed fan. The computer simulation aided in the prediction of overall heat transfer coefficient and conduction heat transfer through wall. The results from numerical study deviated by less than 0.1% when compared with that from the theoretical model.

Dyspnea in Emergency Settings: Up-to-date Diagnosing and Management in the Emergency Department

Abstract Introduction: Dyspnea is a symptom of breathing discomfort sensations generally caused by the disorders of the cardiorespiratory system. Dyspnea is a sign of an emergency where the right treatment and decisions greatly affect the prognosis and mortality. This writing aims to give the latest description of dyspnea, mechanisms, and examination modalities to determine the diagnosis, and management to reduce mortality and worsening of patients in the emergency department. Methods: We searched for articles related to the topics discussed from PubMed’s database from 2013 to 2023 using keywords: Dyspnea and emergency department. We use Mendeley Reference Manager to organize the articles, citations, and references. In total, 57 articles are used as references in this article. Results: Dyspnea is a subjective symptom of breathing difficulty reported by the patient. The intensity of dyspnea might vary depending on the underlying condition and results from interactions between many physiological, social, and environmental elements. Cardiovascular or respiratory diseases are the main causes of discomfort. Anamnesis, physical examination, complete blood count, biomarkers, and chest X-rays can help determine the underlying disease. If the examination results are not supportive, computed tomography scan, lung ultrasonography, and echocardiography can help to make the diagnosis. Not all hospital emergency departments have specialists who can immediately carry out these examinations so understanding and making the right decision by the attending physician is needed to provide the best for the patient.

Frequency of musculoskeletal disorders in Yazd dental laboratory workers at 2019

Introduction: Musculoskeletal disorders are among the main causes of discomfort and disability in dental laboratory workers and are increasing due to the type of occupational tasks of the employees. This study aimed to investigate the prevalence of musculoskeletal disorders in the staff of dental laboratories in Yazd. &#x0D; Materials and Methods: This descriptive cross-sectional study was performed on 37 dental technicians. The Nordic questionnaire was used to collect data on musculoskeletal discomfort. The data was analyzed by SPSS (Ver. 20) using descriptive statistics.&#x0D; Results: The highest frequency of discomfort in the last 12 months was in the lumbar region (43.2%), neck (29.7%), and wrists and hands (21.6%). The highest frequency of musculoskeletal disorders in the last 12 months was in the lumbar region (24.3%), neck (16.2%), back, buttocks and thighs (10.8%). Musculoskeletal disorders in the lumbar (21.6%) and shoulder region (24.3%) were the most common causes of absence from work and job change, respectively.&#x0D; Conclusion: The results of this study showed a high frequency of musculoskeletal disorders in dental laboratory workers, and a high frequency of job change and absence from the workplace due to these disorders.

Development of Equation for Predicting of Outdoor Thermal Comfort for Individuals During Nighttime in Tropical Humid Climate

The sun's heat factor is the leading cause of discomfort when doing outdoor activities, which does not happen at night. However, it is also necessary to ensure that humans feel comfortable at night, even without sunlight. This study aims to develop a regression equation to predict the comfort scale of humans doing outdoor activities at night in humid tropical climates. This study applied a field research method involving 80 adult respondents consisting of 40 men and 40 women in an outdoor location in a humid tropical climate. The data collection method uses a questionnaire. Respondents as subjects were asked about their comfort level when they received local climate penetration that touched their bodies. At the same time, climate variables around the issue were measured. The climate measured consists of air temperature, radiation temperature, relative humidity, and air speed. The data analysis technique is quantitative descriptive. The research results found 2 regression equations, namely for the case of people sitting and walking casually. The regression equation was then validated by comparing it with other equations, namely PMV and PET. The regression equation from this study helps make decisions about facilities and outdoor space design that provide a sense of comfort for humans during the funeral.

Should You Fix Testicular Prosthesis? A Satisfaction Survey From a Monocentric Cohort

Objective:To evaluate whether testicular prosthesis should be fixed MethodsRetrospective monocentric study including 169 patients who had implantation of testicular prosthesis between January 2013 and December 2022. Patients answered a telephone questionnaire regarding prosthesis characteristics and satisfaction. ResultsProsthesis was sutured for 59 patients (34.9%) out of 169. 146 patients answered the questionnaire. Satisfaction was excellent regarding size, weight, consistency and shape. A position too high was a major complain in both groups. Pain and discomfort were significantly higher in the fixed group (30.8% vs 9.78%, p<0,001). Few patients reported discomfort with the anchor prosthesis (22,9%). ConclusionsOverall satisfaction of the prosthesis is high but discomfort and high positioning are the two items remaining to improve. Our study suggests that fixing prosthesis is a cause of discomfort and won’t allow a better positioning

An experimental approach for analyzing pantograph noise contribution

The noise generated from high-speed train is a major cause of discomfort and fatigue for passengers and bystanders. Aero-acoustic noise is particularly troublesome because it increases sharply when train speed increases, as opposed to noise caused by rolling and traction. The main sources of aeroacoustic noise in high-speed trains include the front of the train, the inter-coach spacing, and the pantograph. Of these sources, the pantograph is the only source projected outside of the train in contact with high-voltage electric cables, which transmit electrical power to the train. In this sense, it is difficult to distinguish the characteristics of the noise generated in the pantograph from the noise emitted by each major element by attaching a noise sensor to the pantograph. Therefore, we investigated the characteristics and the influence of the aero-acoustic noise generated from a pantograph using various experimental approaches in a wind tunnel facility.

Development of a decision-support framework to support professionals and promote comfort among older hospital inpatients living with dementia.

Acute hospital wards can be difficult places for many people living with dementia. Promoting comfort and wellbeing can be challenging in this environment. There is little evidence-based support for professionals working on acute care wards on how to respond to distress and maximise comfort and wellbeing among patients living with dementia. Our overall aim was to codesign an evidence-based easy-to-use heuristic decision-support framework, which was acceptable and practical but acknowledges the complex and acute nature of caring for patients with dementia in the hospital. This paper presents the development process and resulting framework. A codesign study was informed by data from (1) a literature review of the care and management of people living with dementia in acute hospitals; (2) a cohort study of comfort and discomfort in people with dementia in acute hospitals; and (3) interviews with family carers and health care professionals. We synthesised evidence from these data sources and presented to key stakeholders through codesign meetings and workshops to produce our decision-support framework. The framework consists of a series of flowcharts and operates using a three-stage process of: (1) assess comfort/discomfort; (2) consider causes of discomfort; and (3) address patient needs to manage the discomfort. Working with key stakeholders, synthesising diverse quantitative and qualitative evidence to build a clinical framework is a feasible approach to help address the needs of patients living with dementia in an acute hospital setting. The result is a framework which is now ready for evaluation and implementation. We worked closely with people living with dementia and family carers throughout this study, including the development of the study protocol with input on study development and design, through to inclusion in stakeholder workshops and codesign of the decision support framework.

Efficacy of topical administration of prallethrin-permethrin-piperonyl butoxide (Bronco® Equine Fly Spray) for the treatment and control of flies and other nuisance insects of horses

Numerous biting and nuisance insects are a noted cause of discomfort and stress to horses. Pyrethrins and pyrethroids have been used for many years in numerous formulations for the control of insect pests in animals, humans and environment. There are, however, few studies reporting their field efficacy in horses. The aim of the present study was to evaluate the repellent activity of a spray formulation based on prallethrin and permethrin synergized with piperonyl butoxide (BRONCO® Equine Fly Spray, Farnam Companies, Inc., USA) against annoying and harmful insects for horses in field conditions. Nine horses of mixed breed were divided into 2 groups (treatment and control). Pre-treatment insect counts were compared to daily counts for 4 days post-treatment (pt). One minute after the administration of the product (day 0), all the horses were negative for the presence of insects. All counts up to the 6-h pt check remained negative for Hippobosca equina, tabanid flies and Simulium spp., showing 100% efficacy. This remained above 90% throughout the study. For the H. equina, the repellent efficacy remained > 99.7% for all 4 days pt, for tabanid flies > 93.3% and for Simulium spp. > 97.4%. The efficacy against Musca spp. decreased from 82.2% at day 0 to 62.2% at day 3. Treatment was well-tolerated. In conclusion, despite the low number of tested horses, Bronco® has demonstrated high insecticide and repellent efficacy and a good persistence, maintained for up to 4 days post-treatment, against the most common species of insects harmful for horses.

Diarrheal woes in transplantation from real world settings with special focus on clostridium difficile infection

BackgroundDiarrhea is the major cause of discomfort and morbidity of patients undergoing hematopoietic stem cell transplant (HSCT). The cause of diarrhea may be infective or non-infective. MethodsThis is a prospective single center observational study from North India conducted over a period of approximately 4 years among 105 patients who underwent HSCT (autologous-72, allogeneic-33). The objective of the study was to identify the overall incidence and characteristics of diarrhea in HSCT in the real world, to evaluate any differences among allogeneic or autologous transplants, incidence of C Difficile among diarrheal patients, and antimicrobial usage among these patients. ResultsDiarrhea was present in 89 of 105 patients (84.7%). The mean diarrheal duration was of 8.39±4.57 days (range: 1–24 days). There was non statistical difference between the incidence of diarrhea amongst allogeneic and autologous transplants (78.9% Vs 87.5%). Out of 89 patients with diarrhea, 13 were CDTA positive. We could isolate Clostridium difficile in culture in only 7.6% of patients with CDTA positivity. Metronidazole was the antibiotic of choice for diarrhea in our post-transplant settings. Metronidazole was prescribed for a median duration of 8 days (Range: 3–18 days). Seventeen patients received oral vancomycin with a median duration of 8 days (Range: 5–14 days). ConclusionWe conclude by saying that diarrhea was a common post-transplant morbidity. Clostridium difficile is not common in patients with the diarrhea post hematopoietic stem cell transplant. All cases of diarrhea need not be infective particularly in allogeneic settings.

Ginger and Warm Water Compress Reduce Complaints of Lower Back Pain in the Elderly in Gaura Village, West Sumba District, Indonesia

Low back pain is among the most frequent causes of discomfort in older adults. Non-pharmacological treatments for patients with low back pain include ginger and heated compresses, which provide a warming sensation and dilate blood vessels to alleviate pain. Objective: to compare the efficacy of ginger and tepid compresses on complaints of lower back pain among older people in Gaura Village, the Gaura Health Center's service area. This study employs a quasi-experimental design with a pre-and post-test. The population of this survey consisted of over-60-year-old residents of Gaura Village, with 17 participants in each group. The sampling technique used consecutive sampling. Independent t-test analysis of the differences between the two variables. The average lower back pain scale before the ginger compress was 6.82, while it was 6.12 before the heated compress. Ginger compression yields an average of 3.82, while mild compression yields 3.82. Ginger compresses alleviate low back pain in older people in Gaura Village, the Gaura Health Center's service area (p-value = 0.000). Warm compresses help lower back discomfort in elderly residents of Gaura Village, where the Gaura Health Center is located (p-value = 0.000). -value 0.167. Ginger and warm compresses can alleviate lower back discomfort in older people in Gaura Village, where the Gaura Health Center is located.

Evaluation of the Hygrothermal Conditions of a Typical Residential Building in the Azores Archipelago

This article contributes to the assessment of the hygrothermal conditions of residential buildings in the Azores archipelago and defines strategies that may contribute to the improvement in indoor air quality. These objectives were fulfilled by in situ monitoring of the hygrothermal conditions of a typical building on Terceira Island. Complementary tests to determine the thermal conductivity of exterior walls and ventilation rates were also conducted. The results were used to validate a simulation model, and different ventilation strategies were simulated using the combined heat, air, and moisture transfer model in EnergyPlus. The model took into account the typical construction methods and materials of the archipelago, as well as the reference weather data sets available for the region. The monitoring campaign showed that the percentage of time in which thermal comfort conditions were achieved was very low, varying from 5% to 32%, being the main cause for discomfort in the humidity level in the indoor environment. The simulation results pointed out the sensitivity of the problem, showing that ventilation may not always be, by itself, beneficial to thermal comfort. In particular, ventilation strategies should be established taking into account additional criteria other than the air change rate, namely the periods of the day and year in which ventilation should be performed, as well as the duration of these periods.

Natural Language Processing and Machine Learning Approach to Teaching and Learning Research Philosophies and Paradigms

The paper cogitates on the critical advent of 4th IR focusing on the concept of machine learning (ML) underpinned by natural language processing (NLP) to demonstrate how research philosophies and paradigms can be better taught and learned for students' benefit. A systematic literature review was earmarked for its depth and textual inquiry from scholarly arguments. The main purpose of this paper is to aver a progressive technological approach towards better comprehensive research paradigms and philosophies, which are complex domains with diverse variety in higher education and a cause of discomfort for students at post-graduate levels. Using quantitative algorithm, the natural language processing and machine learning-inspired digital model poses questions that place students in a reflexive mode and draws their articulated responses as inputs that model their worldviews against a host of philosophies in the database. The paper revealed that, discordant with previous scholars who advocated for a single philosophical assumption for a field, subject or researcher, such as the existence of a pure positivist and/ or pure interpretivist, purist philosophical assumptions should be challenged to benefit students and academics. It means that the digital discovery of research philosophies and paradigms extends the work of previous theorists to the technologically inspired discovery of episteme, ontology and axiology. By its nature, the use of NLP becomes an advanced channel on how we know what we know and the nature of the reality and values being displayed. The paper contributes to the evocation of deep learning arising from new philosophies and methods. The inquiry-based teaching approach transforms learning from the generic push-teaching method that assumes universality to the fostering of a reflexive approach that helps resolve the deep ideological approaches that caused the polarisation. The manner in which NLP and ML are able to extract information relevant to knowledge or philosophical discovery paves the way for approaches that can lead to the depolarisation and decolonisation of research philosophies, which can ultimately boost the development of research students.

Ultrasound Assessment of Abdominal Muscle Thickness With and Without Lumbopelvic Pain in Pregnant Women.

Lumbopelvic pain (LPP) is a very common cause of discomfort during pregnancy, but its etiology remains unclear. The association between abdominal muscle thickness and LPP in pregnant women has not been studied extensively, despite the significant abdominal changes that occur during pregnancy. This study aimed to examine the relationship between abdominal muscle thickness and LPP in pregnant women. In this study, 49 pregnant women in their second trimester participated. The intensity of LPP was assessed using a numerical rating scale. Ultrasound imaging was used to measure the thickness of abdominal muscles, including the rectus abdominis, external oblique, internal oblique, and transversus abdominis muscles. Participants were classified into two groups, the LPP group and non-LPP group, and the abdominal muscle thickness was compared between the two groups. The statistical significance level was set at P < .05. There were 24 and 25 participants in the LPP and non-LPP groups, respectively. Internal oblique (IO) thickness was significantly thinner in the LPP group than in the non-LPP group (5.4 ± 0.2 mm versus 6.1 ± 0.2 mm; P = .042). Multivariate logistic regression analysis showed that IO thickness was significantly associated with LPP (odds ratio, 0.516; 95% confidence interval, 0.284-0.935; P = .019). This study suggested that LPP in second trimester pregnancy might be related to IO thickness. Further longitudinal studies are needed to understand the role of this muscle as an LPP risk factor for pregnant women.

Impact of an Enhanced Transtheoretical Model Intervention (ETMI) Workshop on the Attitudes and Beliefs Regarding Low Back Pain of Primary Care Physicians in the Israeli Navy

Low back pain (LBP) is a major cause of discomfort and disability. Physicians' attitudes and beliefs influence the way patients with LBP are diagnosed and treated. The objective of the study is the assessment of military primary care physicians' attitudes towards LBP and the effect of an enhanced transtheoretical model intervention (ETMI) workshop on them. We evaluated the impact of a 90-min ETMI workshop on the attitudes and beliefs of primary care physicians in the Israeli Navy on LBP. Outcomes were assessed using the Attitudes to Back Pain Scale in Musculoskeletal Practitioners questionnaire (ABS-mp). Participants responded before and after the workshop, and responses were compared to a control group of primary care physicians in the Air and Space Force. The intervention group included 22 participants and the control group included 18 participants. Both groups were heterogenic (gender, age, seniority). In both groups, primary care physicians reported the common use of non-steroidal anti-inflammatory drugs (NSAIDs) and over-the-counter (OTC) pain medications and often included physical activity and physiotherapy in the treatment plan. Physicians mentioned reassurance and suggestions of early return to physical activity as part of their appointment. There was a positive correlation between questionnaire items suggesting the physician tended to a biomedical approach and reporting the use of imaging modalities (r = 0.451, p = 0.005). After attending the workshop, physicians were significantly more likely to recommend an early return to physical activity (18 ± 0.48 vs. 16.4 ± 0.52, p = 0.04). An ETMI workshop had a minor impact on the attitudes and beliefs of primary care physicians regarding LBP, but a statistically significant impact was noted on return to physical activity recommendations. These findings may be important in the military setting.

Modeling the impact of traffic noise: analysis of lightning geometry and its contribution to direct, specular and diffuse path propagation.

The evaluation of urban noise is an important tool in noise control. From existing sources of noise, vehicular traffic is considered the main cause of discomfort in the population. The intensity of the noise that reaches the receiver depends on the level of sound power emitted by the source and the attenuation that occurred in the propagation medium. The analysis of the dispersion of rays in different urban geometries allows the evaluation of parameters that influence the trajectory of noise. The objective of this study is to analyze the contribution of the energy fraction of each path in different urban settings in the global noise, to contribute to the analysis and adoption of mitigating measures. For this, the mathematical model of prediction of noise levels was adopted, which calculates the direct and specular (source-image method) and diffuse (radiosity method) paths. The study was applied in two sectors of the city of Maringá, Brazil. In total, 73200 paths were evaluated in 14640 readings of source positions in 54 measured points. The results showed the part of contribution that each path represents in the acoustic field, and the sound decay caused by obstacles, urban geometry, distance and material properties.

A Rare Anatomical Variation of Upper Multiple Impacted Third Molar

Abstract The third molar is the most commonly impacted tooth which is the cause of pain and discomfort in the second and third decade of life. Therefore, it is the commonly carried out minor surgical procedure which helps remove the cause of discomfort and pain. However, few cases may show no related signs and symptoms and such multiple impacted tooth is found accidently on radiographic findings. This can be removed to avoid discomfort or pain or any pathology in the subsequent period of time. In this case report, we discuss about the multiple impacted upper third molar in a patient, which showed a unique anatomical variation.

Manipulating device-to-body forces in passive exosuit: An experimental investigation on the effect of moment arm orientation using passive back-assist exosuit emulator.

Passive exosuits have been vastly researched in the past decade for lifting tasks to alleviate the mechanical loading on the spine and reduce the lower back muscle activities in lifting tasks. Despite promising advantages of exosuits, factors such as comfort directly influence the user's acceptability of such body-worn devices. Exosuits' routing/anchoring points, which transmit device-to-body forces, remain the leading cause of discomfort among users. In the present study, we sought to investigate the effect of the routing element, that is, the "moment arm," in altering the device-to-body forces and perceived discomfort. We first presented a simplified human-exosuit model to establish insight into the effect of the moment arm on the device-to-body forces acting at the shoulder (FS) and waist (FW). Further, an experimental investigation was conducted on 10 participants with six different exosuit moment arm configurations (C1, C2, C3, C4, C5, and C6) to investigate their effect on the device-to-body forces, perceived discomfort, and muscle activity using a passive back-assist exosuit emulator in a lifting/lowering task. Configuration C4 was found to be most beneficial in reducing device-to-body forces at the shoulder and waist by up to 44.6 and 22.2%, respectively, during lifting. Subjective scores also comprehended with the device-to-body forces, indicating that C4 produces significantly less discomfort for participants. The outcome of the study illustrates the importance of selecting an appropriate moment arm configuration for passive back support exosuits in alleviating the device-to-body forces and perceived discomfort.